It is now generally acknowledged that, if urine drains through an indwelling catheter into a receptacle that does not contain a biocide, then contaminating, unwanted pathogens will multiply rapidly in the receptacle. The presence of the pathogens can lead to serious infections of the urogenital tract in catheterized medical, surgical, gynecological, and urological patients. Since the indwelling catheter and the fluid receptacle are an important component of patient care, patentees Langston, Leeper and Wong in U.S. Pat. No. 4,241,733 provided a patient-care apparatus comprising a container with a device in the container that dispenses formaldehyde for eliminating pathogens, thereby significantly enhancing the practical value and the usefulness of the patient-care apparatus. The device dispensed the biocide formaldehyde at a constant rate that is essentially independent of the volume of fluid present in the container.
It will be appreciated by those versed in the present art that an improvement can be provided in the patient-care apparatus by making available a patient-care apparatus wherein the device dispenses a biocide in an amount corresponding to the volume of fluid in the container. That is, the device dispenses a small amount of biocide when the volume of fluid in the container is small, thereby avoiding an unnecessary high concentration of biocide in the container; and, the device dispenses a correspondingly larger amount of biocide when the volume is larger, thereby providing an amount of biocide needed for substantially eliminating unwanted pathogens.